Peptic ulcers remain one of the commonest causes of acute upper gastrointestinal bleeding. In the past few years, significant progress has been made in the treatment of ulcer hemorrhage, particularly with the increasing development of endoscopic treatments. One method for treating ulcer hemorrhage is endoscopic haemostasis with a thermal probe. When an ulcerated area is observed in the stomach through an endoscope, for example, an RF or other type of thermal probe is applied against the ulcerated area through an endoscope. The thermal probe heats and coagulates the tissue to stop the actual or potential bleeding. To successfully perform a haemostasis, or to prevent future bleeding with a thermal probe, it frequently is necessary to coagulate tissue adjacent to the ulcerated areas visible through an endoscope.
The entire blood vessel needing to be coagulated for successful treatment of a bleeding, or potentially bleeding, ulcer generally is not fully visible through an endoscope. Part of the blood vessel needing to be coagulated generally is underneath the adjacent areas of stomach lining, and it coagulation of this portion of the blood vessel is performed by applying the thermal probe against the mucosal tissue in the stomach above the vessel, coagulating both the vessel and the mucosal tissue. For this reason, the physician applying the thermal probe is often forced to select the specific areas of the tissue to coagulate without full information about the circulatory and other structures underlying the stomach tissue surrounding the all selected areas. Even when the stomach ulcer is visibly actively bleeding at a specific location or when a portion of a blood vessel is visible through an endoscope at a specific location, the physician often lacks full information about the precise location of the remaining portions of the blood vessel needing to be coagulated, which remaining portions are located beneath the stomach lining in the vicinity of the bleeding. Due to these limitations, the physician cannot, as a practical matter, treat an ulcerated condition without also treating visually inaccessible portions of the blood vessel underlying the surrounding stomach tissue that are selection without adequate locating information. Hence, most successful haemostasis procedures with thermal probes heat and destroy not only the blood vessels requiring coagulation, but healthy surrounding tissue that do not need coagulation as well. Indeed, overtreating the area by coagulating portions of the adjacent area that do not need coagulating is the only practical way in the prior art in which the physician can be confident that the entire portion of the blood vessel needing coagulation is properly coagulated. The result of applying a thermal probe to areas not requiring coagulating is, of course, destroying healthy tissue and/or needlessly compromising circulation of blood to substantial areas of the stomach.
It is not uncommon for peptic ulcers to stop bleeding spontaneously, and it is often difficult to predict whether a clotted, non-active site that experienced recent stigmatic bleeding will rebleed, or whether visible blood vessel in a ulcer crater requires the intervention of a thermal probe to coagulate the tissue. For these reasons, decisions as to whether to treat such sites with an endoscopic thermal probe, or to treat the sites with proton pump inhibitors, are frequently controversial. One factor that greatly complicates that diagnostic and treatment decision is the inability of the physician to see or otherwise obtain information about circulatory structures beneath the stomach lining, particularly in those areas adjacent to ulcerated areas of the stomach. Hence, there is substantial need for information about the circulatory structures in these heretofore visually inaccessible areas beneath the stomach lining.